Pumping apparatus for drydock and caisson



A ril 16, 1968 E. w. CRUMLEY PUMPING APPARATUS FOR DRYDOCK AND CAISSON 2 Sheets-Sheet 1 Fi led Feb. 9, 1966 INVENTOR. ERNEST W. CRUMLEY ATTORNEY April 16, 1968 E. w. CRUMLEY PUMPING APPARATUS FOR DRYDOCK AND CAISSON 2 Sheets-Sheet 2 Filed Feb. 9. 1966 INVENTOR. ERNEST W. CRUM LEV ATTORNEY United States Patent 3,377,810 PURWENG APPARATUs FQR DRYDOCK AND CAKSSON Ernest W. Crumley, Apt. 502, fiarlton Arms, Charleston, 5.8. Filed Feb. 9, 1966, Ser. No. 526,148 7 Claims. (Cl. 61-64) ABSTRACT OF THE DIStZLOSURE This invention comprises a floating caisson for sealing the open end of a graving dock. The caisson has a hollow interior containing pumping apparatus including a pump and upper and lower fluid conduits interconnected by a pumping conduit and having open ends communicating with the exterior of the caisson. The lower fluid conduit is provided with secondary conduits communicating with the caisson interior. Valve means are provided in the upper and lower conduits and in the secondary conduits so as to selectively permit Water to be conducted through the caisson and to permit water to be pumped selectively into and out of the dock and caisson interior.

This invention relates to drydocks and more particularly to a pumping apparatus for a drydock of the type including a floating caisson.

In one type of drydock construction in use today, a basin is provided which is of a suitable size for accommodating the types and sizes of ships the drydock is intended to serve. This basin is provided with one end open to the sea through which such ships pass as they enter the drydock basin. In order to seal the basin open end so as to permit dewatering of the drydock, a floating gate or caisson is moved into position adjacent the basin open end after the ship has entered the drydock and water is flooded into the caisson so that the caisson sinks to seal the basin open end. In one type of drydock, a groove is provided in the basin bottom and side Walls for receiving the lower portion of the caisson when it is sunk. This groove is somewhat greater in width than the thickness of the caisson and is of U-shaped cross sectional shape so as to provide oppositely facing sill Walls selectively engageable by the corresponding caisson surface to seal the drydock in one direction to prevent sea water from entering the drydock when it is dewatered or in the opposite direction when the level of water in the drydock is to be raised higher than that of the seawater. The sealing of the drydock open end by engagement of the caisson with that sill wall which faces the drydock baisn permits raising of the water level in the drydock above the sea level. This operation is required for deep draft ships which must be floated higher than the height possible at sea level so as to permit such deep draft ships to be positioned over docking blocks pre-positioned in the basin before dewatering.

The common practice has been to locate the pump or pumps for flooding and dewatering the drydock within the drydock structure and to locate the pump or pumps for dewatering the caisson within the caisson. This application describes in detail the provision of an arrangement in which the caisson and drydock pumping means are combined in a unitary structure which is incorporated in the caisson.

The advantages of incorporating in the caisson the relatively low capacity pumping means for the caisson is widely known as the convenience of such an arrangement is recognized and relatively little pumping is required for floating such a caisson. The incorporation of the drydock pumping means within the drydock structure itself has been Widely used but as can be understood 3,377,310 Patented Apr. 16, 1968 adds considerably to the cost of the drydock posing maintenance problems not only due to the complexity of such installations but due to the tendency of the extended drydock pumping conduits to accumulate foreign matter such as mud carried by the water. In addition, the Wide variety of designs, sizes and other features incorporated within various installations of this general type of drydock requires special adaption and design of the drydock pumping means for each such installation.

Accordingly, a primary object of this invention is to provide a new and novel pumping apparatus for a drydock and floating caisson associated therewith.

Another object of this invention is to provide a new and novel unitary pumping apparatus which is incorporated in a floating caisson for a drydock which may selectively either flood or dewater the dry dock or caisson.

Still another object of this invention is to provide a new and novel pumping arrangement for a floating caisson associated with a drydock which not only permits sluicing of water through the caisson but which may be used selectively to either flood or dewater the drydock or to raise the level of water in the drydock above that of the outside sea level.

Still another object of this invention is to provide a new and novel unitary pumping apparatus for a floating caisson associated with a drydock which eliminates the need for installing drydock pumping means within the drydock structure, which is simple and low cost in construction, which is highly reliable and virtually free from risk of breakdown, which incorporate both the drydock pumping means and caisson pumping means within the caisson and which may be operated at a high pumping rate to either dewater or flood the drydock to raise the water level in the drydock above that of the sea or i to float or sink the caisson.

The objects stated above and other related objects in this invention are accomplished by the provision of pumping apparatus for a drydock and an associated floating caisson of the type having a pair of end walls arranged in spaced parallel relationship, side walls and a bottom Wall defining a hollow interior. The pumping apparatus of the invention includes at least one pumping assembly in the caisson which assembly includes a pump and a pumping conduit extending substantially vertically within the caisson interior. An upper fluid conduit having a pair of open ends is positioned within the upper portion of the caisson interior with the open ends each communicating with the exterior of the caisson through one of the caisson end walls and the upper fluid conduit communicates intermediate its ends with the pumping conduit. Valve means are included for closing each of the open ends of the upper fluid conduit.

'A lower fluid conduit is positioned within the lower portion of the caisson interior adjacent the caisson bottom wall similarly having a pair of open ends communicating with the exterior of the caisson through the caisson end walls and the lower fluid conduit communicates intermediate its ends with the pumping conduit. Valve means are also included for closing each of the lower fluid conduit open ends. At least one secondary fluid conduit is also provided which communicates at one end with the lower fluid conduit and has an open end provided with valve means for communicating the secondary fluid conduit with the interior of the caisson adjacent the caisson bottom wall.

The novel features which are believed to be characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation may be best understood by reference to the following descrip- C tion taken in conjunction with the accompanying drawings in which:

FIGURE 1 is a perspective view of a drydock of the type incorporating the invention;

FIGURE 2 is an end elevation view of a floating caisson of the type associated with the drydock of FIG- URE 1;

FIGURE 3 is a perspective view of the caisson of FIGURE 2;

FIGURE 4 is a perspective view partially broken away of the pumping assembly of the invention;

FIGURE 5 is a perspective view of a portion of the drydock of FIGURE 1;

FIGURE 6 is an enlarged sectional view stantially along line 66 of FIGURE 2;

FIGURE 7 is a sectional view of the caisson and drydock of FIGURE 1 illustrating one operation of the pumping apparatus of the invention;

FIGURE 8 is a view similar to FIGURE 7 showing taken subthe pumping apparatus of the invention in another oporation;

FIGURE 9 is a view similar to FIGURE 7 showing the pumping apparatus of the invention in still another operation; and

FIGURE 10 is an enlarged sectional view of a portion of the caisson and drydock of FIGURE 7.

Referring now to the drawings and to FIGURE 1 in particular, there is shown a drydock designated generally by the letter I) which is situated in the conventional manner adjacent an external body of water such as a sea or river R. The drydock D which is formed generally of concrete or the like is preferably situated in a suitable excavation in the surrounding terrain in the well known manner. The drydock D includes a basin designated generally by the numeral 11 having side walls 12, a closed inner end wall 13 which may be in the form of a ramp or the like and a bottom wall 14 for supporting a ship 16 on docking blocks 17 in the drydock position as shown.

As described in the aforementioned co-pending application, the basin 1]. is provided with an open end 18 which is arranged to be sealed by a floating caisson C as shown best in FIGURES 2, 3. The caisson C is arranged to be received within a groove 19 extending along the basin bottom wall 14 and side walls 12 as shown best in FIGURE 5. The groove 19 is preferably U-shaped in cross section to provide vertically extending sill walls 21, 22 in oppositely facing relationship with sill wall 21 facing inwardly towards the drydock and sill wall 22 facing outwardly towards the sea or river R.

As shown best in FIGURES 7-9, the width of the groove 19 is somewhat greater than the thickness of the caisson C so as to permit the caisson when seated in the groove 19 to be moved selectively into sealing relationship with one of the sill walls 21, 22. Preferably, two such grooves 19 are provided so that at least one groove which is relatively free of obstructions is available at all times.

As shown best in FIGURES 3, 6, the caisson C includes a pair of end walls 23, 24, a bottom wall 25 containing a plurality of spaced recessed portions 27, these recessed portions 27 forming what may be referred to as mud recesses and a pair of side walls 28, 29, the bottom wall 26 and side walls 28, 29 forming a continuous wall as shown best in FIGURE 3. Preferably, the edge portions of the caisson end walls 23, 24 are provided with a relatively narrow sealing strip 31 as shown best in FIG- URES 3, 10 having a suitable recess 32 therein in which is positioned a sealing gasket 33 of resilient material such as rubber or the like.

As specifically illustrative of the invention, the end walls 23, 24, the bottom wall 26 and side walls 23, 29 of the caisson C define a hollow interior 36 in which is positioned at least one pumping assembly designated generally by the letter P in FIGURES 2, 4. In the specific embodiment illustrated, six of such pumping assemblies P are provided as will be explained hereinafter.

A plurality of partitions 37, 33 are provided within the caisson interior which extend vertically from the caisson bottom wall 26 upwardly to a watertight deck 39 in the upper portion of the caisson interior 3%. Each of the partitions 37, 38 are provided with an opening 40 adjacent the caisson bottom wall 26 with which suitable valve means are associated (not sh Wu). The partitions 37, 323 define with the caisson side walls 23, 29 and watertight decks 39, side chambers 41, 42 and the partitions 37, 38 form with each other and the watertight deck 39 a central chamber 43. As shown best in FIGURE 2, a pumping assembly P is provided within each of the side chambers 41, 42 and at least one pumping assembly P, four being provided in the illustrated embodiment, is posidoned within the caisson central chamber 43.

Referring now to FIGURE 4, the pumping assembly P includes a pumping conduit designated generally by the numeral 44 which extends vertically within the caisson interior 36 and comprises a pump column 46 having a lower open end 4dr: encompassed by a well casing 47 in concentric spaced relationship therewith. The upper end of the pump column 46 has connected thereto a pumping unit 43 positioned above the watertight deck 39 to avoid submersion in the water pumped.

An upper fluid conduit or pipe 49 is positioned in the upper portion of the caisson interior 36 and is provided with open ends 51, 52 communicating with the exterior of the caisson C through the caisson end walls 23, 24 as shown. Valve means 53, 5d are associated with the upper fluid conduit ends 51, 52 respectively and are arranged to open and close the ends 51, 52 by suitable actuating means. In the illustrated embodiment, hydraulic valve actuating means 53a, 54:: which may be fluid pressure cylinders or the like are provided for the valves 53, 54 respectively.

The upper fluid conduit 49 communicates intermediate its ends 51, 52 with the pumping conduit 4-4. More specifically, conduit 5e communicates the upper fluid conduit 49 with the upper end of the pump column 46 as shown.

The pumping assembly P also includes a lower fluid conduit 61 positioned in the lower portion of the caisson interior 36 adjacent the bottom wall 26. The lower fluid conduit 61 is similarly provided with open ends 62, 63 which communicate with the exterior of the caisson through the caisson end walls 23, 24. Valve means 64, 66 are provided within the fluid conduit ends 62, as which as described above are arranged to open and close the ends. The movement of valves 64, 66 is controlled by suitable means which preferably include actuating devices such as the hydraulic cylinders 64%;, 66a.

The lower fluid conduit 61 communicates intermediate its ends by means of conduit 67 with the lower portion of the pumping conduit 44. More specifically, the fluid conduit 67 is connected to the well casing 47 and communicates through the wall casing 47 with the lower end 46a of the pump column 46.

The pumping assembly P also includes at least one secondary fluid conduit, two of which being provided in spaced relationship on the lower fluid conduit as shown in FIGURE 4 and identified by the numerals 68, 69. One end of each of the secondary fluid conduits 68, 69 communicates with the lower fluid conduit 61 adjacent the caisson bottom wall 26 within the interior 36 of the caisson and the other ends 70, 71 respectively are open. Suitable valve means such as valves 72, 73 are positioned within the open ends 70, 71 of the secondary fluid conduits 6t}, 69 which are arranged to be actuated by suitable means which include actuating devices 72a, 73a respectively as described above so as to selectively open and close the open ends of the secondary fluid conduits.

The pumping apparatus of the invention is arranged to perform certain pumping operations selectively which include permitting water from the sea or river R to flow into the basin 11 of the drydock D, to flood and dewater both the caisson and the drydock basin 11 above the level of the external body of water or river R. More specifically, there is shown in FIGURES 7-9 the various functions of the pumping apparatus of the invention which may be performed when the caisson C has been sunk into sealing relationship with the groove 19 as described above.

As previously referred to, the pumping apparatus of the invention may be used to flood and dewater the caisson C. More specifically, the smaller pumping assemblies P within the side chambers 41, 42 may be operated to flood the caisson C by opening either or both ends 62, 63 of the lower fluid conduit 61, by means of the vvalves 64, 66. At the same time, one or both of the secondary fluid conduits 68, 69 are opened so that water outside of the caisson C may flow into the interior 36 of the caisson. If faster flooding is desired, it may be accomplished by similarly operating the larger pumping assemblies P in the central chamber 43. When only the pumping assemblies in the side chambers 41, 42 are used, the openings 40 in the partitions 37, 38 permit water flooding into the caisson to be evenly distributed throughout the hollow interior 36 for balancing purposes and the caisson then sinks into the groove 19 as shown in FIGURES 7-9. The ship 16 is, of course, now within the drydock basin 11 and the water level is the same on either side of the caisson C.

When the water level within the drydock basin 11 is to be raised above that of the river, the caisson C is positioned with its sealing member 3-3 on the caisson end wall 23 in sealing engagement with the inwardly facing sill wall 21 as shown in FIGURE 7. The secondary fluid conduits 68, 69 and the end 63 of the lower fluid conduit 61 are closed and the end 52 of the upper fluid conduit 49 is opened. The pumping unit 48 is then operated to pump water fro-m the river R in the direction of the arrows through conduit 61, the upper fluid pump column 46 and conduit 49 into the interior of the drydock basin 11 as shown in FIGURE 7.

To dewater the drydock D, the caisson C must be shifted to the right as shown in FIGURE 8 with the sealing member 33 in engagement with the outwardly facing sill wall 22 as shown in FIGURE 8. The caisson C must be floated again to permit this shift to be made and this is accomplished by opening the ends 70, 71 of the secondary fluid conduits 68, 69 respectively, closing the ends 62,63 of the lower fluid conduit 61 and opening one or both of the ends 51, 52 of the upper fluid conduit 49. Preferably, only the pumping assemblies P in the side chambers are again used; but if desired, the larger pumping assemblies may be employed and the water within the caisson interior 36 enters the secondary fluid conduits and the lower fluid conduits 61 to be pumped up the pump column 46 and out of the open ends of the upper fluid conduit 49. The caisson C being slightly buoyant may now be shifted over to the position of FIGURE 8 and sunk again in the previously described manner.

Referring now to FIGURE 8, the pumping assemblies P are also used to dewater the basin 11 of the drydock D. To accomplish the drydock dewatering operation with the caisson in the position of FIGURE 8, valves 54, 64 in the ends 52, 62 of the upper and lower conduits 49, 61 respectively are closed, secondary fluid conduits 68, 69 being also closed and the opposite ends 51, 63 of conduits 49, 61 respectively are opened. The pumping unit 48 is then operated to pump the water out of the dry dock basin 11 into the river R in the direction indicated by the arrows in FIGURE 8.

It will be noted in FIGURE 8 that the water pumped out of the drydock enters the open end 63 of the lower fluid conduit 61 and is conducted upwardly through pump column 46 into conduits 56 and 49 and out of the open conduit end 53. In order to rapidly dewater the drydock whereby the ship 16 is seated on the docking blocks 17, all of the pumping assemblies P in the caisson C may be used. By way of example, a drydock of 29 million gallons capacity utilizing pumping assemblies P in the number and size previously referred to may be emptied in approximately 58 minutes.

The pumping assemblies P are also used for filling the drydock basin 11 in the manner shown in FIGURE 9. To accomplish this drydock filling operation, the ends of either or both of the upper and lower fluid conduits 49, 61 may be opened so that the water enters the drydock basin 1]. through the conduits in the direction shown by the arrows in FIGURE 9. Water flowing into the dry dock basin 11 through the conduits 49, 61 under the head of water in the external sea or river R would thus bring the level of water within the basin 11 up to the corresponding river level.

While there has been described what at present is considered to be the preferred embodiment of the invention, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the invention and, therefore, it is the aim of the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

Having thus described the invention, what is claimed is:

1. Pumping apparatus for a drydock and associated floating caisson having a pair of end walls arranged in spaced, parallel relationship, side walls and a bottom wall defining a hollow interior, the combination which comprises, at least one pumping assembly in said caisson, said pumping assembly including a pump, a pumping conduit extending substantially vertically within said caisson interior, an upper fluid conduit positioned within the upper portion of said caisson interior and extending transversely of said caisson, said upper fluid conduit having a pair of open ends each communicating with the exterior of said caisson through one of said end walls and communicating intermediate said ends with said pumping conduit, valve means associated with said upper fluid conduit for closing said upper conduit open ends, a lower fluid conduit positioned within the lower portion of said caisson interior adjacent said bottom wall and extending transversely of said caisson, said lower fluid conduit having a pair of open ends each communicating with the exterior of said caisson through one of said end walls and communicating intermediate said ends with said pumping conduit, valve means associated with said lower fluid conduit for closing said lower conduit open ends, at least one secondary fluid conduit communicating with said lower fluid conduit to selectively conduct water into and out of said caisson inte rior, said secondary fluid conduit having an open end communicating with the interior of said caisson adjacent said bottom wall and valve means associated with said secondary fluid conduit for closing said secondary conduit open end, said upper and lower conduits being thereby arranged to conduct water through said caisson and to conduct water pumped into and out of said drydock and caisson.

2. Pumping apparatus in accordance with claim 1 wherein said apparatus includes a pair of said secondary fluid conduits arranged in spaced relationship intermediate the ends of said lower fluid conduit and wherein valves means are associated with each of said secondary fluid conduits.

3. Pumping apparatus in accordance with claim 1 wherein said caisson includes a plurality of partitions in said hollow interior, said partitions defining a central chamber and a chamber adjacent each caisson side wall, and wherein at least one pumping assembly is provided in each of said chambers.

4. Pumping apparatus in accordance with claim 3 including an opening in each of said partitions adjacent said caisson bottom wall to thereby provide fluid communication between said chambers.

5. Pumping apparatus in accordance with claim 4 wherein the pumping capacity of the pumping assembly in said central chamber is substantially greater than the pumping capacity of the pumping assembly in each of said side chambers.

6. Pumping apparatus in accordance with claim 5 wherein one pumping assembly is provided in each of said side chambers and wherein a plurality of pumping assemblies is provided in said central chamber.

7. Pumping apparatus for a drydock and associated floating caisson having a pair of end walls arranged in spaced parallel relationship, side walls and a bottom wall defining a hollow interior comprising, in combination, a horizontally extending watertight deck in the upper portion of said caisson hollow interior, a pair of partitions extending vertically within said hollow interior between said caisson bottom wall and said watertight deck each adjacent one of said caisson side walls, said partitions forming with said caisson side walls and with each other a pair of side chambers and a central chamber respectively, at least one pumping assembly in each of said chambers, said pumping assembly including a pump having a motor positioned above said watertight deck, a pumping conduit including a well casing and a pump column arranged in spaced concentric relationship extending substantially vertically within said chamber, an lpper fluid conduit positioned within the upper portion of said chamber and extending transversely of said caisson, said upper fluid conduit having a pair of open ends each communicating with the exterior of said caisson through one of said end walls and communicating intermediate said ends with said pumping conduit, a valve in each of said upper conduit open ends, means for moving said valves between an open and closed position, a lower fluid conduit positioned within the lower portion of said chambers adjacent said bottom wall and extending transversely of said caisson, said lower fiuid conduit having a pair of open ends each communicating with the exterior were of said caisson through one of said end walls and com- ,iunicating intermediate said ends with said pumping conduit, a valve in each of said lower conduit open ends, means for moving said valves between an open and closed position, a pair of secondary fluid conduits communicating at one end with said lower fluid conduit to selectively conduct water into or out of said caisson, each of said secondary fluid conduits having an open end communicating with the interior of said chamber adjacent said bottom wall and a valve associated with said secondary conduit open end, means for moving said valve between an open and closed position, an opening in each of said partitions adjacent said caisson bottom wall to thereby provide fluid communication between said chambers, said pumping assemblies in said central chamber having a capacity substantially greater than the pumping capacity of the pumping assemblies in each of said side chambers, said upper and lower conduits being thereby arranged to conduct water through said caisson and to conduct wate pumped into and out of said drydock and caisson.

References Cited UNITED STATES iATENTS JACOB SHAPIRO, Primary Examiner. 

